During filming, a small problem arose from the decision to change Benoit's surname from Jules to Roget: the name plate for actor André Maranne's outfit had already been prepared bearing the initial 'J', and there was no way to change it in a timely manner. To compensate, Maranne was given a neckerchief to wear to cover the offending letter.
This episode was wiped by the BBC and no copy of it is known to exist. Both it and The Moonbase: Episode 3 (1967) are among the 97 episodes of Doctor Who (1963) that are missing from the BBC archives.
This episode takes place on the Moon in 2070.
During the initial release of these episodes on VHS in Cybermen: The Early Years (1992), Colin Baker mistakenly claimed that Jamie contracted the disease that was affecting the members of the moonbase. He was actually injured moon walking. This error likely stems from the fact that the audio of the story had not yet been discovered.
The working title for this story was The Return of the Cybermen.